Mold filling apparatus including a discharge door with flexible leading edge



May 31, 1966 A. G. GRANATH 3,253,305

MOLD FILLING APPARATUS INCLUDING A DISCHARGE DOOR WITH FLEXIBLE LEADING EDGE 2 Sheets-Sheet 1 Filed Sept. 6, 1963 w me Wig 1N VENTOR.

May 31, 1966 A. G. GRANATH 3,253,305

MOLD FILLING APPARATUS INCLUDING A DISCHARGE DOOR WITH FLEXIBLE LEADING EDGE Filed Sept. 6,

2 Sheets-Sheet 2 \9 3 INVENTOR.

United States Patent O 3,253,305 MUILD FllLLllNG APPARATUS INCLUDING A DIS- CHARGE DOOR WITH FLEXIBLE EDGE Axel G. Granath, Chicago, 111., assignor to Herbert Simpson Corporation, Chicago, 11]., a corporation of Illinois Filed Sept. 6, 1963, Ser. No. 307,042 2 Claims. (Cl. 22-36) The present invention relates generally to apparatus for feeding material and more particularly to new and improved apparatus for filling foundry mold flasks with foundry sand.

In filling mold flasks it is highly desirable that the sand immediately adjacent the pattern be packed into the flask with less density to permit expansion of the metal during molding operation while at the same time requiring the sand at the outside of the flask to be packed with greater density to prevent mold disintegration during handling of the filled flasks.

Accordingly, it is an object of the present invention to provide new and improved apparatus for filling mold flasks with foundry said wherein the sand immediately adjacent the pattern is deposited loosely thereon in an aerated condition and then the flask is rapidly filled up with densely packed sand to provide a strong mold which will withstand rough handling without breakage or disintegration of the sand in the mold.

Previously, such devices for filling mold flasks have been complicated and cumbersome in that they generally included two or more belt conveyors, a vibrating screen or riddle and a centrifugal sand slinger and at least two discharge mechanisms, one for depositing the loosely packed sand and another for depositing the densely packed sand into the mold flasks. It is therefore another object of the present invention to provide a new and improved apparatus for filling molding sand wherein a single mechanism is provided to deposit sand in the flask initially in a loosely packed state and then in a densely packed state.

Another object of the present invention is the provision of a new and improved apparatus as described above which is simple in operation and construction, relatively small in size, virtually foolproof and dependable in op eration and relatively inexpensive to construct and operate.

Briefly, these and other objectsand advantages of the of the present invention are accomplished by the provision of a new and improved method for filling mold flasks with foundry sand wherein flasks to .be filled are positioned below a single sand filling apparatus and initially a thin stream of moving sand is directed into the flask around the pattern therein in an aerated and loosely packed condition. After the pattern is sufliciently covered with the loosely packed sand, a rapid flow of sand is directed into the flask in a tightly packed condition until the flask is full in order to back up the loose sand and thus provide a strong mold in which the sand will not readily disintegrate if handled roughly. The apparatus of the present invention comprises a hopper positioned above the flasks to be filled for holding a supply of foundry'sand. The hopper is provided with a sloping wall having an enlarged opening adjacent the lower end thereof. An endless belt conveyor is positioned to underlie the enlarged opening and is provided LEADING ice with a downwardly moving cleated belt which moves in a plane coincident with the sloping wall of the hopper thus acting as a downwardly moving wall of the hopper to drag sand from the bottom thereof directly into the flask. The lower end of the hopper is provided with an opening adjacent the upper surface of the belt and a movable discharge door is provided to 'control the size of the opening and thus control the discharge of the sand.

In filling a flask, the discharge door is initially maintained in a closed position wherein only a small clearance is present between the leading edge of the door and the upper surface of the moving belt. in this position, only a small amount of sand is dragged out of the bottom of the hopper through the small clearance by the cleats on the belt and is deposited in a thin stream into the mold flasks. This dragging action thoroughly aerates the sand and deposits it loosely on the pattern in the mold flask directly below. When the pattern is covered with an appropriate amount of loosely packed sand, the discharge door is opened widely, and the head of the sand in the hopper plus the action of the belt direct a large amount of said downwardly into the flask to tightly packed and fill the flask.

For a better understanding of the present invention, reference should be had to the following detailed description when taken in conjunction with the drawings, in which:

FIG. 1 is a cross-sectional view of the mold flask filling apparatus of the present invention taken substantially along line 1--1 of FIG. 4;

FIG. 2 is an enlarged, fragmentary, detailed view of one of the side walls of the discharge chute shown in FIG. 1;

FIG. 3 is an elevational view partly in section of the apparatus of FIG. 1 taken substantially along the line 33 of FIG. 4;

FIG. 4 is a side elevational view of the apparatus of FIG. 1; and

FIG. 5 is a detailed view of the discharge door of the apparatus of FIG. 1.

Referring now more particularly to the drawings, there is illustrated an apparatus indicated generally by the reference numeral 10 for filling moldflasks with molding sand and constructed in accordance with the features of the present invention. The apparatus 10 includes a hopper 12 containing a supply of molding sand 14. The hopper is provided with side walls 16 and a sloping bottom wall 18 which has an enlarged opening 20 defined adjacent the bottom end thereof.

Positioned to underlie the enlarged opening 20 in the sloping bottom wall 18, there is provided an endless belt conveyor mechanism indicated generally by the reference numeral 22. The conveyor mechanism 22 includes an endless rubber belt 24 having transverse ridges or cleats 24a thereon and the belt is positioned to completely cover the enlarged opening 20 of the sloping wall 18 and lie in a plane which is generally coincident therewith. The belt 24 moves downwardly in the direction shown by the arrows 26 and forms a downwardly traveling bottom wall for the hopper 12. The ridges 24a of the belt can be integrally formed on the outer covering of the belt and can be triangular in cross-section as shown, or other type of cleats such as wood slats may be bolted to the belt.

The conveyor 22 is provided with a frame structure in- With the door I cluding side channels 28 and cross-members 3t), and a plurality of backing boards 32 are secured to the cross-members to provide backing support for the moving belt 24. The forward end of the conveyor is provided with a takeup pulley 34 mounted on a take-up shaft 36 which is supported for rotation by a pair of take-up bearings 38. The bearings 38 are mounted on angle brackets 40 secured to the side channels 28 and adjusting means 42 are provided to move the bearings as necessary to adjust the tension on the belt.

The belt is driven by a head pulley 44 carried on a head shaft 46 which is supported for rotation in a pair of bearings 48 supported on angle brackets 50 attached to the side channels 28. The head shaft 46 is driven by means of a torque arm gear reducer 52 carried on one end thereof. The reducer 52 is driven by a belt 54 and electric motor 56 which is adjustably mounted on a motor base 58 attached to one of the side members 28. The motor base 58 is additionally secured to the sloping wall 18 of the hopper by an angle member 69 which is welded to the wall 18 as well as to the ends of the side member 28. The lower end of the conveyor 22 is supported from the hopper by means of side angles 64 which are attached to the side walls 16 of the hopper.

In order to prevent sand from the hopper from leaking out between the upper end of the conveyor 22 and the upper edge 20a of the opening 20 in the sloping wall 18 of the hopper, there is provided a strip of belting material 66 which is adapted to overlie the belt 24 at the point where it starts its downward travel along the hopper bottom. of the side walls 16 are in close proximity to the upper surface of the traveling belt to prevent leakage of sand along the side of the conveyor.

The lower end of the hopper 12 is provided with an enlarged discharge hood 68 having side walls 70, a top wall 72 and a front wall 74. This hood is provided in order to maintain a large quantity of sand in readiness for rapid discharge from the hopper. The lower end of the hood is open as at 76 so that a large quantity of sand can be rapidly discharged therethrough.

In order to control the discharge of sand from the discharge hood 68, there is provided a clam-shell door 78' having a pair of side walls 80 which are pivotally secured to the side walls 70 of the hood by means of pivot pins 82. The clam-shell door is provided with a curved forward door plate 84 (FIG. which is curved on a slightly larger radius than the lower ends of the side walls 78 of the hood. The curved door 84 is provided with a leading edge 84a which is recessed back from the lower edges 80a of the sides 8%) in order to accommodate a strip of flexible rubber belting 86 which is secured to the door 84 by means of a metal strip 88 and bolts 90. The strip of belting 85 forms a transverse flexible leading edge for the clam-shell door and when the door is in the closed position as shown in FIG. 5, the strip is positioned to engage the upper surface and ridges 24a of the mov-, ing belt 24. Movement of the clam-shell door about the pins 82 in the direction as shown by the arrow 92 is accomplished and controlled by means of an air or hydraulic cylinder 94, having one end pivotally attached to a bracket 96 of the hopper and the other end pivotally attached to a bracket 98 on the clam-shell door. In order to confine the stream of sand as it discharges from the hood 68 when the clam-shell door is opened widely, there is provided a discharge chute 106 which is supported from the side channels 28 by means of a pair of angle frames 102. The chute has a pair of opposed side walls 104 having lower edges formed by flexible rubber strips 166 positioned to engage the upper surface of the belt 24.. These strips are adjustable for wear and are held in position by means of metal strips 168 and bolts 110.

Prior to operation of the apparatus, the hopper 12 is filled with molding sand 14 while the clam-shell door 78 is in the closed position as illustrated in FIG. 4 A mold In addition, as is seen in FIG. 2, the lower edgesflask to be filled is positioned below the discharge chute and the belt conveyor 22 is then started by the operator. As the belt 24 moves in the direction shown by the arrows 26 with the clam-shell door 78 in the closed position, only a small amount of sand is dragged from the hopper because of the interaction between the ridges 24a of the moving belt 24 and the flexible strip 86 of the clamshell door. This small flow of sand is directed downwardly in a thin stream in the general direction of the arrows 111 into the flask to be filled. Because of the relatively thin stream of flowing sand and the flexing action of the strip 86 relative to the moving cleats or ridges 24a on the belt, the flowing sand is thoroughly aerated as it falls downwardly into the flask to loosely cover the mold pattern therein. During this time, sand is loosely packed around the pattern and in a well aerated condition so that the mold will permit the metal to expand during the molding process.

After a coating of loosely packed sand has covered all parts of the pattern within the mold flask tothe desired depth, the cylinder 94 is actuated. to open widely the clam-shell door 78 and thus provide for a rapid discharge or dumping of the sand from the discharge hood 68 of the hopper into the flask. Because the door is opened widely, and there is little or no obstruction to the flow of sand, and because of the action of the moving belt under the influence of the head pressure of the sand in the hopper, the sand is rapidly dumped into the flask in a tightly packed condition to back up the loosely packed sand immediately adjacent the mold pattern in the flask. This produces a mold flask which is strong and will resist crumbling or disintegration during rough handling, yet still provides for expansion of the metal in the mold because of the loosely packed sand immediately adjacent the metal.

From the foregoing description, it can be seen that the present invention provides a new and improved method of filling mold flasks with sand which is efficient and rapid and does not require complex apparatus as have previous methods. ent invention is easy to operate and construct, rapid and reliable in operation and accomplishes the desired result with a minimum of moving parts.

While a particular embodiment of the present invention has been shown and described, it will be understood that various modifications will occur to those skilled in this art and, it is, therefore, contemplated by the appended claims to cover all such modifications that fall within the true spirit and scope of the invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. Apparatus for directly filling mold flasks with granular material comprising hopper means positioned above said flasks for holding a supply of said granular material, said hopper means having a sloping wall with an enlarged opening adjacent the lower end thereof, endless belt conveyor means positioned to underlie said enlarged opening, said conveyor means including a transversely cleated belt moving downwardly along a plane substantially coincident with said sloping wall forming a downwardly traveling moving wall portion and a discharge door pivotally secured at the lower end of said hopper means, said door having a flexible leading edge extending transversely a distance at least equal to said enlarged opening, means for moving said leading edge into and out of engagement with said belt to control the discharge of said granular material moving with said conveyor means out of said hopper means, whereby said leading edge flexes in response to engagement with said cleats when said leading edge is engaged with said belt thereby facilitating the discharge of aerated granular material.

2. Apparatus as defined in claim 1 wherein there is additionally included a discharge chute positioned downwardly from said discharge opening having a pair of side walls extending along opposite sides of said belt conveyor Moreover, the apparatus of the presand a top Wall joined thereto, said side Walls having flexible strips along the lower edges thereof adapted to closely overlie the upper surface of said moving belt.

References Cited by the Examiner UNITED STATES PATENTS Richards 19853 Wangelin 22-35 Kissel 198-S3 Bliss 2236 Beardsley et al 2235 Muir et al ,198-54 Fernald 22-89 Beech 2236 Dietert 22-89 J. SPENCER OVERHOLSER, Primary Examiner.

MARCUS U. LYONS, Examiner. Carr 198-54 10 R. D. BALDWIN, Assistant Examiner. 

1. APPARATUS FOR DIRECTLY FILLING MOLD FLASKS WITH GRANULAR MATERIAL COMPRISING HOPPER MEANS POSITIONED ABOVE SAID FLASKS FOR HOLDING A SUPPLY OF SAID GRANULAR MATERIAL, SAID HOPPER MEANS HAVING A SLOPING WALL WITH AN ENLARGED OPENING ADJACENT THE LOWER END THEREOF, ENDLESS BELT CONVEYOR MEANS POSITIONED TO UNERLIE SAID ENLARGED OPENING, SAID CONVEYOR MEANS INCLUDING A TRANSVERSELY CLEATED BELT MOVING DOWNWARDLY ALONG PLANE SUBSTANTIALLY CONCIDENT WITH SAID SLOPING WALL FORMING A DOWNWARDLY TRAVELING MOVING WALL PORTION AND A DISCHARGE DOOR PIVOTALLY SECURED AT THE LOWER END OF SAID HOPPER MEANS, SAID DOOR HAVING A FLEXIBLE LEADING EDGE EXTENDING TRANSVERSELY A DISTANCE AT LEAST EQUAL TO SAID ENLARGED OPENING, MEANS FOR MOVING SAID LEADING EDGE INTO AND OUT OF ENGAGEMENT WITH SAID BELT TO CONTROL THE DISCHARGE OF SAID GRANULAR MATERIAL MOVING WITH SAID CONVEYOR MEANS OUT OF SAID HOPPER MEANS, WHEREBY SAID LEADING EDGE FLEXES IN RESPONSE TO ENGAGEMENT WITH SAID CLEATS WHEN SAID LEADING EDGE IS ENGAGED WITH SAID BELT THEREBY FACILITATING THE DISCHARGE OF AERATED GRANULAR MATERIAL. 